1. Technical Field
The present disclosure relates to a board apparatus including a printed circuit board.
2. Description of the Related Art
A printed circuit board is provided to mount various active elements or various passive elements thereon, and to implement a circuit for a predetermined function. In addition, the printed circuit board includes a ground supply for electrical stability and noise emission of each circuit. When insulation of the ground supply is secured, that is, a ground environment is poor, stability and reliability of a board apparatus including the printed circuit board may be degraded.
As an example, the printed circuit board of a motor driving apparatus may be provided with an electromagnetic compatibility (EMC) filter for minimizing an introduction of EMC into a motor and an inverter for supplying a three-three alternating current (AC) signal to the motor.
Here, each of the EMC filter and the inverter is connected to the ground supply GND for electrical stability.
Since a typical ground supply GND supplies a voltage of 0V, whether or not a ground wiring of the EMC filter and a ground wiring of the inverter are electrically connected through the ground supply GND does not need to be considered.
In a case in which the ground environment of a place where the motor driving apparatus is installed is poor, however, the ground wiring of the EMC filter and the ground wiring of the inverter may be electrically connected through the ground supply GND. Thereby, the EMC emitted from the ground wiring of the EMC filter and conduction noise emitted from the ground wiring of the inverter may be introduced into the EMC filter or the inverter. In this case, stability and reliability of the apparatus may be degraded.
Therefore, the motor driving apparatus needs to include a switch for interrupting the connection between the ground wiring of the EMC filter and the ground wiring of the inverter, depending on the ground environment.